This invention relates in general to the manufacture of electrical terminals such as those found in electrical connectors. In particular, this invention relates to an improved method of forming an electrical terminal for an electrical connector that reduces manufacturing costs.
Electrical connectors often include a male terminal which is inserted into a separate female terminal. The male and female terminals are each connected to a desired electrical component or power source to complete an electrical circuit when the male and female terminals are in contact with one another. Contact surfaces on the male and female terminals include electrically conductive material, such as copper, silver, and precious metals, that provides an electrical path between the male and female terminals.
The cost of desirable electrically conductive metals, especially copper and precious metals, is high relative to the overall cost of the electrical connector in which such metals are used. Attempts have been made to reduce the cost of manufacturing electrical terminals by various methods. For example, it is known to add a clad interface layer to an electrical terminal base by welding or soldering, or to weld an electrical wire to an electrical terminal base. Welding, however, may negatively alter the mechanical properties of the welded material, may cause oxidation, and may result in undesirable micro-voids at the interface of the base material and the electrically conductive material.
It is also known to electro-plate precious metal, i.e., expensive electrically conductive metal, to only selected portions of an electrical terminal base. This process however, results in increased costs associated with additional process steps, may require customized material inventory management systems, and the wet chemical process associated with electro-plating requires additional, and often cumbersome, hazardous waste management processes. It is further known to use copper clad aluminum as the base material, but the increased cost of copper negates any potential savings from process efficiencies. Additionally, it is known to form the electrical terminal base from aluminum rather than copper, and then add a clad interface layer by welding or soldering. This method of forming an electrical terminal requires bonding a transition layer of material between the electrical terminal base and the precious metal to be clad to allow soldering, and may require a burnishing or cleaning process to remove surface oxides from the electrical terminal base. It would therefore be desirable to provide an improved method of forming an electrical terminal for an electrical connector that reduces the amount of precious metal used, and therefore reduces manufacturing costs.